1. Field of the Invention
The present invention relates to a time correcting method of automatically correcting a time of a timer and a portable remote telephone terminal having a timer in which a time is corrected in accordance with the time correcting method.
2. Description of the Related Art
In general, a portable remote telephone terminal has a timer indicating the present time. In a case where a user having such a portable remote terminal moves in areas between which there is a difference in time, it is preferable that the time of the timer is easily corrected.
The portable remote telephone terminal has a constitution corresponding to types of service systems. There are an analog system and a digital system as the types of service systems. As the analog system, an AMPS (Advanced Mobile Phone Service) system, a TACS (Total Access Communications System) and an NTT system have been known. As the digital system, a PDC (Personal Digital Cellular) of a TDMA system, a GSM (Global System for Mobile Communications), and an IS-95 (cdmaOne) of a CDMA (Code Division Multiple Access) system have been known.
The portable remote telephone terminal has a timer and the present time is indicated in a display unit. When a user uses the portable remote telephone terminal for the first time, the user initially sets the present time of the timer. The portable remote telephone terminal in which a calling time period can be indicated by using a function of the timer has been known. A base station for the portable remote telephone services supplies various types of information to portable remote telephone terminals in a service area.
The portable remote telephone service system is formed so as to be capable of supplying services in a wide area. As a result, an area in which a user of the remote portable telephone terminal can move is expanded. A user having the remote portable telephone terminal may move from one area to another area between which areas there is the difference in time. For example, there is one hour difference between Chicago and New York. Thus, in a case where a user sets the time of the portable remote telephone terminal in New York and then moves to Chicago, the time obtained in the portable remote telephone terminal differs from the actual local time in Chicago.
Due to an automatic answering/recording function of the personal remote telephone terminal, a receiving time at which a message is received is recorded with the message. If the time obtained in the portable remote telephone terminal is not correct based on the difference in time, the receiving time recorded in the portable remote telephone terminal is not correct. In addition, in a case where times at which data is transmitted and received are recorded, the recorded times may not be corrected. Thus, every time the user having the portable remote telephone terminal moves in areas between which there is the difference in time, the user has to do an operation for resetting the timer of the portable remote telephone terminal to the local time. The operation is troublesome for a user who frequently moves in areas between which there is the difference in time.